Two coupled bugs in our endpoint that the runner just surfaced:
1. The runner mounts \$CLIENT_DOWNLOADS to /downloads as a Docker volume
(per quic-interop-runner's docker-compose.yml `client.volumes`).
There is no DOWNLOADS env var. Our endpoint was reading \$DOWNLOADS,
getting null, and (for handshake/chacha20) skipping any download path.
Hard-code /downloads.
2. The handshake / chacha20 / handshakeloss testcases don't just verify
the handshake completes — they also require the requested file at
/downloads/<basename>. The runner's _check_files validator
reported "Missing files: ['intense-tremendous-firefighter']" while
our client side reported `handshake ok`. Route handshake-flavor
testcases through runTransferTest so the full H3 GET pipeline runs.
`chacha20` keeps the cipher-suite override (ChaCha20-only ClientHello);
`handshakeloss` reuses the same H3 flow against a lossy sim.
Also drops the now-dead runHandshakeTest + parseFirstTarget helpers.
https://claude.ai/code/session_01HcvfQq1ttPV9PkRoJb4nyT
Claude
04bbb4e3e9